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Saline Wastewater Treatment Plant Project Nears Completion

The City of Saline has been spending millions to upgrade and maintain its water systems with the largest expense being the $3.6 million upgrade of the Wastewater Treatment Plant (WWTP). At the Monday night City Council meeting, Brian Ruble, an engineer from Tetra Tech, reviewed ongoing water projects that Tetra Tech has been overseeing in Saline.

Work on the WWTP should be nearing completion. A month ago the city set an August 15 deadline for completion, but Ruble suggested the project may come in late.

“I don’t think it will be months, but it may be days,” Ruble said.

The upgrade has included repairs and replacements for many parts of the sewage treatment system. One of these is a rebuilt septage handling facility.

For the uninitiated, “septage” is a polite term for the material which is pumped out of septic tanks. The city not only process its own waste from the sewer system, but also the septage hauled in by septic tank pumping operations. It is a source of revenue.

In its process, the WWTP uses equipment called Rotating Biological Contactors (RBCs). RBCs are large banks of rotating disks that are coated with a biofilm (bacteria in a slime matrix). As they rotate through contaminated water and air, the bacteria break down organic contaminants.

These disks weigh thousands of pounds so mechanical parts tend to wear out. These have been rehabilitated.

One of the last steps in wastewater processing is passage through a tertiary filter. The old system involved passage through sand and had become only marginally effective. New technology makes this process more effective and more efficient.

The tertiary filter assemblies have now been replaced. Ruble noted that they are “still working through some start-up bugs,” but “every day it gets a little better.”

Among other parts that have been replaced in the new system are: the RBC drive, a new clarifier drive, new control panels, a new septage processing unit and an activated carbon odor control unit.

Councilman Dean Girbach asked how the upgrades would improve efficiency. Ruble replied that the biggest saving would be reduced staff time needed to keep the system functioning.

Girbach also asked if there would be better tracking of drop-offs by septage haulers. Ruble said that with the new system, haulers will need to use a swipe card and new software will keep track of every transaction.

Mayor Brian Marl said that the progress is all very exciting, to the extent that one can be excited by sewage treatment. He also commented on the long upgrade process and possible problems in the future.

“We do apologize for any inconveniences that have been associated with this project, but with a project of this magnitude there are going to be delays; there are going to be inherent hardships,” Marl said. “I do want to remind people it is still a wastewater treatment plant and there will still be some issues and some odors, regrettably.”

Ruble also spoke of other water projects. One of these was a water reliability study.

The Michigan Clean Water Act requires that a study be done every five years. Ruble called it “kind of a checkup of how your water system is doing.”

This includes assuring adequate fire flow, and making map updates. A new post-Flint requirement is to report the diameter, material and age of the pipes throughout the system.

The data has been gathered to the extent possible, Tetra Tech is doing engineering analysis and a final report should be completed in the fall.

Tetra Tech has also been working on a Utility System Development Charge Study, to determine appropriate pricing for water and sewer connections. This should also be completed soon.

Another Tetra Tech project is the GIS Map Update. In April, after snow melt but before the trees leafed out, Ruble and DPW Director Jeff Fordice collected GPS data on storm water outfalls in the city. Updated maps will be available this fall.

“In 2015 Saline was only eight spots away from being funded,” Ruble said. “So you are the eighth community down in the next year’s cycle. We are very optimistic that come October you’re going to get a nice letter from the state with just shy of a million dollars award for this program. So this will help develop an asset management plan for your waste water system, your plant, your sewer and you also requested money for your storm water system.”

Ruble added that there are no guarantees. Still, the presentation ended on this very positive note.

Bob Conradi Is a retired pharmaceutical scientist who has redefined himself as a photographer and journalist. He has lived in Michigan for 36 years and in the Saline area for 10. He enjoys researching and learning about new ideas. Reach him at [email protected] Follow him on Twitter at @RobertConradi.